TWO large objects identified by satellite in the Indian Ocean off Perth may be related to missing Flight MH370 and are “possible indications of debris”.

Describing the “credible sightings” as the best lead investigators currently have, Australian Maritime Safety Authority general manager John Young said the objects were “relatively indistinct on imagery”.

One was about 24-metres long, approximately double the length of a standard shipping container, while the other one was smaller.

“Those who are experts indicate they are credible sightings,” Mr Young told a press conference in Canberra this afternoon. “The indication to me is of objects that are of reasonable size and awash with water, bobbing up and down on the surface.”

A US Navy P8 Poseidon aircraft is already in the remote search area, which is about 2,500km southwest of Perth, and a RAAF Orion aircraft is expected to arrive later this afternoon. Additional aircraft are also expected to follow for a more intensive search.